"""Read model for the task REST collection and detail endpoints."""

from django.contrib.contenttypes.models import ContentType
from django.db.models import Count, IntegerField, OuterRef, Prefetch, Q, Subquery, Value
from django.db.models.functions import Coalesce

from communications.models import Message
from tasks.access import task_board_access_q
from tasks.models import (
    Task,
    TaskAttachment,
    TaskBoard,
    TaskLinkedObjectKind,
)


def task_api_queryset(*, user, params):
    task_content_type = ContentType.objects.get_for_model(Task)
    comments_subquery = (
        Message.objects.filter(
            chat__type="comments",
            chat__context_content_type=task_content_type,
            chat__context_object_id=OuterRef("pk"),
            is_deleted=False,
        )
        .values("chat")
        .annotate(count=Count("id"))
        .values("count")
    )
    queryset = (
        Task.objects.filter(board__is_archived=False)
        .filter(board__in=TaskBoard.objects.filter(task_board_access_q(user)))
        .select_related(
            "board",
            "column",
            "row",
            "created_by",
            "assignee",
            "cover",
            "cover__attachment",
            "cover__attachment__uploaded_by",
            "cover__comment",
            "cover__comment__author",
            "cover__external_link",
            "cover__external_link__created_by",
            "cover__linked_object",
            "cover__linked_object__content_type",
        )
        .prefetch_related(
            "labels",
            "participants",
            "checklist_items",
            Prefetch(
                "cover__comment__task_attachments",
                queryset=TaskAttachment.objects.select_related("uploaded_by"),
            ),
        )
        .annotate(
            linked_posts_count=Count(
                "linked_objects",
                filter=Q(linked_objects__kind=TaskLinkedObjectKind.POST),
                distinct=True,
            ),
            linked_messages_count=Count(
                "linked_objects",
                filter=Q(linked_objects__kind=TaskLinkedObjectKind.MESSAGE),
                distinct=True,
            ),
            linked_events_count=Count(
                "linked_objects",
                filter=Q(linked_objects__kind=TaskLinkedObjectKind.CALENDAR_EVENT),
                distinct=True,
            ),
            linked_documents_count=Count(
                "linked_objects",
                filter=Q(
                    linked_objects__kind=TaskLinkedObjectKind.DOCUMENT,
                ),
                distinct=True,
            ),
            linked_requests_count=Count(
                "linked_objects",
                filter=Q(
                    linked_objects__kind=TaskLinkedObjectKind.REQUEST,
                ),
                distinct=True,
            ),
            linked_procurement_requests_count=Count(
                "linked_objects",
                filter=Q(
                    linked_objects__kind=(TaskLinkedObjectKind.PROCUREMENT_REQUEST),
                ),
                distinct=True,
            ),
            linked_employees_count=Count(
                "linked_objects",
                filter=Q(
                    linked_objects__kind=TaskLinkedObjectKind.EMPLOYEE,
                ),
                distinct=True,
            ),
            linked_guests_count=Count(
                "linked_objects",
                filter=Q(
                    linked_objects__kind=TaskLinkedObjectKind.GUEST,
                ),
                distinct=True,
            ),
            linked_guest_visits_count=Count(
                "linked_objects",
                filter=Q(
                    linked_objects__kind=TaskLinkedObjectKind.GUEST_VISIT,
                ),
                distinct=True,
            ),
            linked_attendance_records_count=Count(
                "linked_objects",
                filter=Q(
                    linked_objects__kind=(TaskLinkedObjectKind.ATTENDANCE_RECORD),
                ),
                distinct=True,
            ),
            linked_objects_count=(
                Count("linked_objects", distinct=True)
                + Count("external_links", distinct=True)
            ),
            comments_count=Coalesce(
                Subquery(comments_subquery, output_field=IntegerField()),
                Value(0),
            ),
            attachments_count=Count("attachments", distinct=True),
            checklist_total=Count("checklist_items", distinct=True),
            checklist_completed=Count(
                "checklist_items",
                filter=Q(checklist_items__is_completed=True),
                distinct=True,
            ),
        )
    )
    if board := params.get("board"):
        queryset = queryset.filter(board_id=board)
    if column := params.get("column"):
        queryset = queryset.filter(column_id=column)
    if row := params.get("row"):
        queryset = queryset.filter(row_id=row)
    if assignee := params.get("assignee"):
        queryset = queryset.filter(assignee_id=assignee)
    if priority := params.get("priority"):
        queryset = queryset.filter(priority=priority)
    if params.get("unassigned") == "true":
        queryset = queryset.filter(assignee__isnull=True)
    return queryset